Light weight, hinged self-closing container covers and combination flex-torsion springs for use with such covers

Abstract

Combination flex and torsion springs for use with light weight covers for containers having self-closing gates, the springs operatively connecting the gates to surrounding cover portions. A tri-fold seam including a frangible seam works cooperatively with the flex-torsion springs to implement three modes of operation of the gates. In a first mode, the gate returns to a reclosed orientation after removal of downward pressure. Further pressure on the gate engages a toggle operation that locks the gate open. In a third mode, if the gate is pushed even further downward, the toggle mechanism is defeated and the combination flex-torsion spring is forced past its elastic limit and the gate remains in a permanently open orientation. The flex-torsion springs in accordance with the invention may be fabricated from aluminum sheet stock or spring wire.

What is claimed is: 
     
         1 . A combination flex and torsion spring, comprising:
 a) a central portion having a pair of opposing side edges, a front edge a rear edge, and means for fastening said central portion to an external surface;   b) a pair of elongated, arcuate arms, each having a proximal end and a flattened region adjacent a distal end thereof, a first of said pair of elongated, arcuate arms being attached to a first of said pair of opposing side edges and extending outwardly therefrom, a second of said pair of elongated, arcuate arms being attached to a second of said pair of opposing side edges and extending outwardly therefrom; and   c) a camming structure operatively connected to said central portion proximate said front edge of said central portion.   
     
     
         2 . The combination flex and torsion spring as recited in  claim 1 , wherein said central portion comprises an elongated, tongue-like forward projecting flex spring portion extending from said front edge of said central portion. 
     
     
         3 . The combination flex and torsion spring as recited in  claim 2 , wherein said elongated, tongue-like forward projecting flex spring portion comprises a distal end having a through hole therethrough. 
     
     
         4 . The combination flex and torsion spring as recited in  claim 2 , further, comprising:
 d) at least one through hole in at least one of the locations selected from the group: said flattened region of said first of said pair of elongated, arcuate arms, said flattened region of said second of said pair of elongated, arcuate arms, a distal end of said forward facing flex spring portion, and said central region; and   e) means for fastening associated with and operatively connected to said at least one of said at least one through hole.   
     
     
         5 . The combination flex and torsion spring as recited in  claim 4 , wherein said means for fastening comprises at least one selected from the group: a fastener, a stake, and a quick cure adhesive. 
     
     
         6 . The combination flex and torsion spring as recited in  claim 1 , wherein said combination flex and torsion spring is formed from a thin piece of aluminum. 
     
     
         7 . The combination flex and torsion spring as recited in  claim 6 , wherein said thin piece of aluminum comprises one of the forms selected from the group: an aluminum sheet, and an aluminum spring wire. 
     
     
         8 . The combination flex and torsion spring as recited in  claim 6 , wherein said thin piece of aluminum comprises a 5052-H10 aluminum alloy. 
     
     
         9 . The combination flex and torsion spring as recited in  claim 5 , wherein said selected thin piece of aluminum has a thickness in the range of approximately 0.006 inch to 0.007 inch. 
     
     
         10 . The combination flex and torsion spring as recited in  claim 1 , further comprising:
 d) a pair of detent tabs operatively attached to respective ones of said pair of arcuate elongated arms, a first of said pair of detents being attached to a first of said pair of arcuate elongated arms and a second of said pair of detent tabs being attached to a second of said pair of arcuate elongated arms.   
     
     
         11 . The combination flex and torsion spring as recited in  claim 10 , wherein said camming structure comprises a curvilinear portion sized and configured to capture and retain a portion of at least one of said pair of detent tabs when a gate of a container cover to which said combination flex and torsion spring is attached is opened and moved to a predetermined position.